Jørn Dyerberg

The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010?

Current dietary recommendations advise reducing the intake of saturated fatty acids (SFAs) to reduce coronary heart disease (CHD) risk, but recent findings question the role of SFAs. This expert panel reviewed the evidence and reached the following conclusions: the evidence from epidemiologic, clinical, and mechanistic studies is consistent in finding that the risk of CHD is reduced when SFAs are replaced with polyunsaturated fatty acids (PUFAs). In populations who consume a Western diet, the replacement of 1% of energy from SFAs with PUFAs lowers LDL cholesterol and is likely to produce a reduction in CHD incidence of ≥2-3%. No clear benefit of substituting carbohydrates for SFAs has been shown, although there might be a benefit if the carbohydrate is unrefined and has a low glycemic index. Insufficient evidence exists to judge the effect on CHD risk of replacing SFAs with MUFAs. No clear association between SFA intake relative to refined carbohydrates and the risk of insulin resistance and diabetes has been shown. The effect of diet on a single biomarker is insufficient evidence to assess CHD risk. The combination of multiple biomarkers and the use of clinical endpoints could help substantiate the effects on CHD. Furthermore, the effect of particular foods on CHD cannot be predicted solely by their content of total SFAs because individual SFAs may have different cardiovascular effects and major SFA food sources contain other constituents that could influence CHD risk. Research is needed to clarify the role of SFAs compared with specific forms of carbohydrates in CHD risk and to compare specific foods with appropriate alternatives.

Nutrition transition and its relationship to the development of obesity and related chronic diseases

The prevalence of overweight and obesity has also increased substantially in the nutritional transition countries, and the health burden of obesity‐related complications is growing. The introduction of fast‐food chains and Westernized dietary habits providing meals with fast‐food characteristics seems to be a marker of the increasing prevalence of obesity. The mechanisms involved are probably that the supply of foods is characterized by large portion sizes with a high energy density, and sugar‐rich soft drinks. The high energy density of foods is partly brought about by a high dietary fat content, and it has been shown that even in a Chinese population the increase from about 15% to 20% in the proportion of calories from fat is sufficient to explain some weight gain in the population. In addition, fast food from major chains in most countries still contains unacceptably high levels of industrially produced trans fatty acids that have powerful biological effects, and contribute to type 2 diabetes and coronary artery disease. New evidence also suggests that a high intake of trans fat may produce abdominal obesity, an important factor in the metabolic syndrome, type 2 diabetes and cardiovascular disease. The optimal diet for the prevention of weight gain, obesity, metabolic syndrome and type 2 diabetes is fat‐reduced, without any industrially produced trans fatty acids, fibre‐rich, high in low energy density carbohydrates (fruit, vegetables and whole grain products) and with a restricted intake of energy‐containing drinks.

Bioavailability of marine n-3 fatty acid formulations.

The use of marine n-3 polyunsaturated fatty acids (n-3 PUFA) as supplements has prompted the development of concentrated formulations to overcome compliance problems. The present study compares three concentrated preparations - ethyl esters, free fatty acids and re-esterified triglycerides - with placebo oil in a double-blinded design, and with fish body oil and cod liver oil in single-blinded arms. Seventy-two volunteers were given approximately 3.3g of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) daily for 2 weeks. Increases in absolute amounts of EPA and DHA in fasting serum triglycerides, cholesterol esters and phospholipids were examined. Bioavailability of EPA+DHA from re-esterified triglycerides was superior (124%) compared with natural fish oil, whereas the bioavailability from ethyl esters was inferior (73%). Free fatty acid bioavailability (91%) did not differ significantly from natural triglycerides. The stereochemistry of fatty acid in acylglycerols did not influence the bioavailability of EPA and DHA.

Effects of trans- and n-3 unsaturated fatty acids on cardiovascular risk markers in healthy males. An 8 weeks dietary intervention study.

Background: Studies of long-term intake of industrially produced trans fatty acids (TFA) and n-3 polyunsaturated fatty acids (PUFA) suggest opposite effects on cardiovascular disease risk. Common mechanisms of action are probable.Objective: To examine the effects on cardiovascular risk markers of dietary enrichment with TFA or n-3 PUFA.Design: Randomized, double-blind, parallel intervention trial.Setting: Department of Human Nutrition, The Royal Veterinary and Agricultural University.Subjects: In all, 87 healthy males included, 79 completed.Intervention: Subjects were randomly assigned to 8 weeks of a daily intake of 33 g of experimental fats from either partially hydrogenated soy oil containing 20 g of TFA, 12 g of fish oil with approximately 4 g of n-3 PUFA and 21 g of control fat, or 33 g of control fat. The experimental fats were incorporated into bakery products. Plasma lipids, blood pressure, heart rate variability (HRV), arterial dilatory capacity, compliance, and distensibility were recorded before and after intervention and at follow-up 12 weeks after the intervention.Results: High-density lipoprotein cholesterol (HDL-C) decreased in the TFA group and triglycerides and mean arterial blood pressure decreased in the n-3 PUFA group compared to the control group. HRV, arterial dilatory capacity, compliance, and distensibility were unchanged.Conclusion: The results indicate that the association between coronary heart disease risk and intake of TFA and n-3 PUFA relates only modestly to changes in traditional risk markers.Sponsorship: Danish Medical Research Council (Grant no. 22-01-0390), Center of Advanced Food Research (Copenhagen, Denmark) (Grant no. KVL-R-2001-107), the Danish Heart Association (Grant no. 99-2-3-45-22748), Novozymes (Bagsvaerd, Denmark), Aarhus Olie (Aarhus, Denmark), and from private sources. The experimental fats were provided by Pronova Biocare (Aalesund, Norway) and Aarhus Olie (Aarhus, Denmark).

Fast food: unfriendly and unhealthy.

Although nutrition experts might be able to navigate the menus of fast-food restaurant chains, and based on the nutritional information, compose apparently ‘healthy’ meals, there are still many reasons why frequent fast-food consumption at most chains is unhealthy and contributes to weight gain, obesity, type 2 diabetes and coronary artery disease. Fast food generally has a high-energy density, which, together with large portion sizes, induces over consumption of calories. In addition, we have found it to be a myth that the typical fast-food meal is the same worldwide. Chemical analyses of 74 samples of fast-food menus consisting of French fries and fried chicken (nuggets/hot wings) bought in McDonalds and KFC outlets in 35 countries in 2005–2006 showed that the total fat content of the same menu varies from 41 to 65 g at McDonalds and from 42 to 74 g at KFC. In addition, fast food from major chains in most countries still contains unacceptably high levels of industrially produced trans-fatty acids (IP-TFA). IP-TFA have powerful biological effects and may contribute to increased weight gain, abdominal obesity, type 2 diabetes and coronary artery disease. The food quality and portion size need to be improved before it is safe to eat frequently at most fast-food chains.

Intake of ruminant trans fatty acids in the Danish population aged 1-80 years

Objective:To estimate the intake of ruminant trans fatty acids (TFA) in the Danish population aged 1–80 years.Design:Descriptive study.Subjects:A sex- and age-stratified random sample drawn from the Danish Civil Registration System. A total of 3098 participants (51% female) aged 1–80 years were included. The participation was 66%.Dietary information:A 7-day dietary record.Results:The estimated median intake of ruminant TFA was 1.4 g/day with the 80% central range being from 0.9 to 2.1 among children aged 1–6 years and 1.6 g/day (1.0–2.4) among children aged 7–14 years. The median TFA intake was 1.8 g/day (0.9–2.9) among adults aged 15–29 years and among adults aged 30–80 years. The intake expressed as percentage of energy intake was 0.8, 0.6, 0.7, and 0.7, respectively. Dairy products were the main source of ruminant TFA.Conclusions:The median intake of ruminant TFA in the Danish population aged 1–80 years is estimated to be 1.7 g/day (0.9–2.7), corresponding to 0.7% of energy intake (0.5–1.0), with dairy products being the main source of ruminant TFA.Sponsorship:The Danish Heart Foundation (Grants 02-2-9-8-22010 and 03-2-9-4-22087) and the Female Researchers in Joint Action (FREJA) programme from the Danish Medical Research Council.

What Went In When Trans Went Out

Despite the obvious theoretical health benefits of replacing trans fatty acids with other fatty acids in food products, concern has been expressed that this change might increase the intake of satu...

Plasma homocysteine, angiographically proven coronary artery disease, and wine consumption.

BACKGROUND: Plasma total homocysteine (p-tHcy) is considered to be an independent risk factor for atherosclerotic vascular disease. This cross-sectional study was undertaken to examine p-tHcy levels and their relationship to coronary artery disease (CAD) and alcohol intake. METHODS: We consecutively studied 291 patients referred for elective coronary angiography due to suspected CAD. The patients completed an alcohol questionnaire, and blood samples were drawn after an overnight fast for measurement of p-tHcy. RESULTS: Patients without CAD (n=85) had significantly lower p-tHcy (10.1+/-4.7 μmol/l) than patients with at least one significant coronary artery stenosis (n=206, p-tHcy: 11.9+/-6.4 μmol/l). Patients with a previous myocardial infarction (MI; n=74) also had a higher p-tHcy (12.3+/-4.0 μmol/l) than patients without MI (n=217; p-tHcy: 10.7+/-6.2 μmol/l). Patients with a daily intake of wine (n=30) had lower p-tHcy (9.4+/-2.8 μmol/l) than patients who did not drink wine (n=47; p-tHcy: 12.1+/-6.0 μmol/l; P<0.05), independent of age, prior MI, and degree of CAD. CONCLUSIONS: p-tHcy correlated positively with CAD. There was an inverse correlation between p-tHcy and wine consumption, suggesting a new potential mechanism by which wine consumption may lower the risk of CAD.

Trans fatty acids in adipose tissue and risk of myocardial infarction: A case-cohort study

Background The risk of coronary heart disease associated with intake of individual trans fatty acids (TFAs) is not clear. Adipose tissue content of TFAs is a biomarker of TFA intake and metabolism. Objective We investigated the rate of myocardial infarction (MI) associated with the adipose tissue content of total 18:1t, isomers of 18:1t (18:1 Δ6-10t and 18:1 Δ11t) and 18:2 Δ9c, 11t. Methods A case-cohort study, nested within the Danish Diet, Cancer and Health cohort (n = 57,053), was conducted, which included a random sample (n = 3156) of the total cohort and all incident MI cases (n = 2148) during follow-up (14 years). Information on MI cases was obtained by linkage with nationwide registers and validated. Adipose tissue was taken from the participants buttocks and the fatty acid composition was determined by gas chromatography. Results Women with higher adipose tissue content of total 18:1t had a 57% higher MI rate (quintiles 5 versus 1, hazard ratio, 1.57; 95% confidence interval, 1.12–2.20; P-trend = 0.011) and women with higher content of 18:1 Δ6-10t had a 76% higher MI rate (quintiles 5 versus 1, hazard ratio, 1.76; 95% confidence interval, 1.23–2.51; P-trend = 0.002). No association between 18:1 Δ11t content and MI rate was observed. In men, no associations between adipose tissue content of total 18:1t and 18:1 Δ6-10t and MI rate were observed. However, men with higher content of 18:1 Δ11t had a 48% higher MI rate (quintiles 5 versus 1, hazard ratio, 1.48; 95% confidence interval, 1.17–1.86; P-trend = 0.003). Adipose tissue content of 18:2 Δ9c, 11t was not associated with MI rate in women or men. Conclusions Adipose tissue content of 18:2 Δ9c, 11t was not associated with MI rate in women or men, whereas higher contents of isomers of 18:1t were associated with higher MI rates but the associations for individual 18:1t isomers differed, however, in women and men.

Reliability of nutritional labelling of fast-food

Elevated body weight and fat distribution are disproportionately increasing in immigrant children world-wide. As there is concern that high blood pressure (BP) is a consequence, we investigated this relationship between various measures of overweight/obesity and blood pressure (BP) in four ethnic groups of nine year old children, living in inner city Sydney, Australia. School children (n=1232) selected from inner city Sydney schools were classified as normal, overweight or obese based on measures of body mass index (BMI), waist and total body fat. Where the birth country of the child or a parent was in Europe (20%), the Middle-East (ME) (11%), or Southeast Asia (SEA) (18%) the child was classified as belonging to that ethnic sub-sample. Estimates of children’s exercise patterns were recorded both at school and outside school. Systolic BP was significantly associated with all overweight/obesity measures, however diastolic BP was not. The systolic BP relationship was most pronounced (Pearsons correlation coefficient = 0.5 P<0.000) in both the SEA and ME sub-samples who had 17% and 14% obesity rates respectively compared to six percent for Australians. Obese SEA and ME children had a significant 12-fold/19-fold increased risk of high systolic BP (> 121). All migrant children reported lower levels of exercise and were significantly more likely not to participate in organised sports than their Australian peers (Odds Ratios: ME=3, SEA=5, EUR OR=2); although they were equally, or more (SEA) likely to exercise during school time. We concluded that it is important to implement culturally acceptable exercise and extracurricular sports’ programs. T4:PO.03